Ocular fixation and macular integrity by microperimetry in multiple sclerosis

Area of Science:

• Ophthalmology
• Neurology
• Vision Science

Background:

• Multiple sclerosis (MS) is a demyelinating disease affecting the central nervous system.
• Optic neuritis (ON) is a common initial manifestation of MS, potentially leading to long-term visual impairment.
• Assessing macular integrity and fixation stability is crucial for understanding visual dysfunction in MS.

Purpose of the Study:

• To characterize macular integrity and fixation stability in individuals with MS, comparing those with and without a history of ON.
• To utilize microperimetry (MP) as a tool for evaluating visual function in MS patients.

Main Methods:

• Fifty-five eyes from MS patients (divided into groups with no ON, previous ON, and previous contralateral ON) and 43 healthy eyes were analyzed.
• Microperimetry (MAIA) was used to assess average macular threshold (AT), fixation indexes (P1, P2), bivariate contour ellipse area (BCEA), and fixation ellipse axes (H, V).

Main Results:

• All MS groups showed significantly reduced average macular threshold (AT) compared to controls (p < 0.001).
• Eyes with previous ON demonstrated a more pronounced reduction in AT (p < 0.001).
• Fixation parameters differed significantly between controls and MS patients with ON (p < 0.02), with disease severity correlating with fixation patterns.

Conclusions:

• Macular sensitivity is compromised in MS patients, especially those with prior ON.
• MS patients with ON exhibit fixational instability, characterized by increased vertical (V) axis of the fixation area.
• Disease severity in MS correlates with altered fixation patterns, highlighting the impact on visual stability.